title: Breastfeeding and the risk of childhood Hodgkin lymphoma: a systematic review and meta-analysis.
abstract: OBJECTIVE
  Numerous observational epidemiological studies have evaluated associations between breastfeeding and the risk of childhood Hodgkin lymphoma; however, the existing results are inconsistent. We therefore conducted a systematic review and meta-analysis.
  
  
  METHODS
  Medical literature was searched in the Pubmed and Embase databases to identify all English-language relevant studies up to April 10, 2013. Reference lists were thereafter hand-searched for additional articles. Studies that reported relative risk ratios (RRs) or odds ratios (ORs) with 95% confidence intervals (CIs) were included. This meta-analysis was conducted in accordance with the guidelines for the meta-analysis of observational studies in epidemiology.
  
  
  RESULTS
  We finally included 10 case-control studies in our meta-analysis, involving 1,618 childhood Hodgkin lymphoma cases and 8,181 controls. Overall, we did found a borderline significant association between breastfeeding and reduced risk of childhood Hodgkin lymphoma comparing ever breastfed children to never breastfed children (pooled OR =0.79; 95%CI, 0.58-1.08; P=0.13), with limited evidence for between-study heterogeneity (P =0.12, I2 = 35.70%).
  
  
  CONCLUSIONS
  There is limited evidence for an inverse association between breastfeeding and risk of childhood Hodgkin lymphoma.
authors.affiliation: Department of Pediatric Surgery, Qilu Hospital of Shandong University, Jinan, Shandong, China E-mail : zhuangyan2211@126.com.
authors.forename: Ke-Lai
authors.initials: KL
authors.lastname: Wang
authors.forename: Chun-Lan
authors.initials: CL
authors.lastname: Liu
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhuang
authors.forename: Hong-Yi
authors.initials: HY
authors.lastname: Qu
mesh_terms: D002648:Child; D006801:Humans; D001942:Breast Feeding / Q000009:adverse effects; D016022:Case-Control Studies; D006689:Hodgkin Disease / Q000209:etiology; D011379:Prognosis; D012307:Risk Factors